Improved feed-water heater for locomotives



Nrrnv TAT-Es' BENJAMIN CRAWFGRD, OF ALLEGHENY, PENNSYLVANIA.

IMPROVED FEED-WATER HEATER FOR-LOCOMOTIVES.

Specication forming part of Letters Patent No. 38,730, dated June .42, 1863; antedated v November 16, 1862.

To all whom t may concern:

Be it known that I, BENJAMIN CRAWFORD, of Pittsburg, in the county of Allegheny and Sta-te of Pennsylvania, have invented a new and useful Improvement in Modes of Heating Feed-Water for Locomotives 5 and I do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming part of this specification, in which- Figure 1 is a top view of a portion of a lo'- comotive with my improvements applied to it. Fig. 2 is a partial side elevation and section ofthe same. Fig. 3 is a transverse section of the front part of the boiler and smoke-stack with the escape and branch pipes in position.

Similar letters of reference in the several figures indicate corresponding parts.

The nature of my invention consists in an arrangement for heating feed-water for locomotives, which', at the will of the engineer, takes a portion of the exhaust-steam out of the blast-pipes or escape-nozzles at points immediately under the smoke-stack and conducts it into the feed-water-heater chamber,

and, under certain contingencies at the will of the operator, discharges a portion of the same into the open atmosphere-this organization operating in conjunction with escapenozzles or draft-pipes which have their termini contracted to a greater extent than usual, and, while it is serving to heat the feed-water, not materially impairing the draft of the engine nor allowing injurious back-pressure upon the pistons, but, when serving especially for discharging the exhaust-steam through the heater into the atmosphere, decreasing or checking the draft to any degree desired, and thus preventing the back-pressure upon the pistons due to a strong draft through contracted nozzles, and also obviating the use of a damper or variable or expanding and contracting nozzles.

To enable others skilled in the art to make and use my invention,I will proceed to describe its construction and operation with reference to the drawings.

The feed-water heater A is similar in its form and make to those in vgeneral use on stationary high-pressure engines. It is, under my organization, connected to the escape-pipes B B by the branch pipes C C. By this arrangement the usual method of escaping the steam through the heater for the purpose of hea-tin g the feed-water is superseded, and only so much of the escape-steam is taken by the branch pipes C from the pipes B B and conducted into the heater as may be required to heat the feed-water, leaving the residue to escape in the usual way to produce the blast for the furnace. In the upper part of the heater a valve, D, is arranged, so as to open and close the escape-passage A' accordingly, as circumstances mayA require. This valve answers a twofold purpose-viz: To relieve the heater -of undue pressure and also to allow steam to escape when it is desirable to decrease thedraft of thefurnace. There is-a similar valve, E, provided to each of the branch pipes C O for regulating the quantity of steam admitted from the escape-pipes B intoy the heater or out of the heater into the atmos phere. The valve D and those E E are connected to rods F and G G, which extend back into the engineers apartment of the engine, so as to be readily operated as occasion may require The supply-pipe H of the heater is connected to a suitable pump worked by the engine and drawing water from the tender and forcing itinto the heater at its top through the strainer I. The conveyer-pipe J is attached near the bottom of the heater, and therefrom 'leads to and connects with the force' pump, which forces the heated water into the boiler in the usual manner.

The proportion of the escape-steam required to heat the feed-water to 2120 will ordinarily beabout one-sixth part of the whole amount escaping from the engine. This would very materially affect the blast produced by the escaping steam into the smoke-stack if no provision were made to restore its efficiency. Therefore, to guard against any deflcieny in the blast, it is necessary to reduce the size of the nozzles of the escape-pipes B fully in proportion or a little more than is due to the quantity of steam used in heating the water.

This quantity of steam, however, will vary in accordance with the different circumstances under which the feed-water is liable to be used, the difference in the quantity and temperature at which it enters the heater, which may at times produce too much blast and consequently an unnecessary back-pressure upon the pistons of the engine. In order to meet any such contingency, the valves E E and D are provided. The valves E, being placed in close proximity to the escape-pipes, the steam in escaping from the cylinder finds no space for its expansion, whereby its force would become weakened until it leaves the termini of the escape-nozzles and enters the smoke-stack, and therefore this arrangement with the reduction in the diameter of the nozzles admits of the necessary amount of escape-steam beingadmitted through the valves into the heater without any detrimental effect upon the blast or draft being experienced, which quantity can be controlled by the engineer, as he has control of the valves. Again, the valve D being placed in the escape-passage of the heaterv and under the control of the engineer, it, by being opened, will relieve the heater and the engine-pistons of any unduel back-pressure, whether the same is caused by the draft being too great, by reason of contracted nozzles, or by reason of the condition and quantity in which the steam and water enter the heater.

The tubing of the locomotive-boileris so small that it requires a heavy blast to produce a sufficient draft to get the Water heated to the proper temperature; but by heating the feed-water as proposed by me the draft wouldnot be required to be so strong to produce the same amount of steam.

- The advantages to be gained by the use of my invention, are- First. By supplying with the hot water, instead of with cold water, a large saving of fuel will be effected While the engine is doing a given amount of work or duty; or otherwise the saine amount of fuel will produce a much larger amount of useful eect-either in speed or in additional load or draft-which in the latter case is adding greatly to the value of the locomotive, as it adds greatly to its capacity in power. It should be here noticed that unused live steam is not consumed in heating the feed-water, but that exhaust or waste steam is the agent employed.

Second. The engineer can, to an extent suficient for all practical purposes, regulate the draft of his furnace at his pleasure by admitting more or less of the escape-steam through the heater, instead of using a damper for that purpose. The advantage in this would be, when the blast was reduced in this way, the cylinders would be relieved of a large amount of back pressure, which always attends a heavy blast, and, in fact, the effect of the operation of these valves for this purpose would be the same as an expanding and contracting nozzle to the blastpipes, an arrangement that has been recommended by high authority on locomotives for the purpose of relieving the cylinders from back-pressure.

Third. By supplying with hot water, instead of cold, the boilers are not so liable to unequal expansion and contraction, a thing` which often seriously injures the boilers and tubing.

Fourth. The supply-water tothe boilers will be about sixteen per cent. purer, as about that amount of steam will be condensed in the heater and added to the supply, which will, to that extent, produce no sediment or fouling to the boiler and tubing.

Fifth. The heat of the re required to generate a sufficient quantity of steam to produce vthe power required is so greatthat the reboxes soon burn out. To overcome this difficulty copper has, in many cases, been substituted, and now experiments with `steel plates as substitutes for copper are being made. Now, it is very certain that it does not require anything like as hot a fire to produce a given amount of power while supplying the boilers hot Water as while supplying with cold 5 consequently, forthe same amount of work done, the fire-boxes would last much longer.

What I claim as my invention, and desire to secure by Letters Patent, is

1. The arrangement, substantially as herein described, for heating feed-water for locomotives by exhaust-steam taken from the blastpipes at a point or points below the chimney or smokestack, as herein set forth.

2. The valvesE E, applied and operated between the blast-pipes B B and the heater A, substantially as and for the purpose described.

3. The valve D, applied and operated substantially in the manner and for the purpose described.

BENJ. CRAWFORD. Witnesses:

REDuoND J. GRACE, THOMAS SNoWDEN. 

